X-ray tube control



E. B. GRAVES 2,583,213

x-RAY TUBE CONTROL Filed March 26, 1948 Jan. 22, 1952 FIG-3 FIG-5 INVENTOR. EDWARD B. GRAVES BY www@ Mm ATTORNEYS Patented Jan. 22, 1952 X-RAY TUBE CONTROL Edward B. Graves, nSouth Euclid, Ohio, assignor to Picker X-Ray Corporation Waite Manufacturing Division, Inc., Cleveland, Ohio, a corporation of Ohio Application March 26, 1948, Serial No. 17,211

(Cl. Z50-62) 4 Claims.

This invention relates to improvements in X- ray tube control and more particularly to improved means for preventing spoiled radiographs whenfusingBucky grid technique.

An object of the presentl invention is to provide means to compel the presetting or preparation of a Bucky grid for an excursion before making a radiographic exposure.

Another object of the present invention is to so coordinate a cassette or film holder together with a Bucky grid control means that the cassette must be in its proper place and the Bucky grid mustbe ready and prepared for an excursion before an X-ray exposure can be initiated.

Other objects and advantages of the present invention will be apparent from the accompanying drawings and description and the essential features thereof will be set forth in the appended claims.

In the drawings, Fig. 1 is a top plan view of one form of my device with a portion of the grid broken away to moreV clearly show the construction;

Fig. 2 is. an enlarged transverse sectional view of the same taken along the line 2-2 of Fig. 1;

Fig. 3 is an enlarged fragmental sectional view taken from approximately the position of the line 3--3 of Fig. 1;

Fig. 4 is a diagrammatic view illustrating the wiring and operation of the form of the device shown in Figs. 1, 2 and 3;

Fig. 5 is a fragmental sectional View of a portion of Fig. 1 showing a modied form of my device;

While Fig. 6 is an enlarged fragmental sectional View taken along the lines E-S of Fig. 5,

f In making a radiograph utilizing a Bucky grid, quite often the operator will forget to latch up the moving grid, when it is spring driven, or otherwise forget to prepare the Bucky grid for an excursion before initiating an exposure. In such a case, if he tries to make an exposure. he gets a picture of a lot of lead strips instead of a proper radiograph. The present invention compels the proper presetting of the grid for an excursion and the placing of a cassette in the tray ready for a radiograph and both of these are so coordinated that they must be in proper condition before the initiation of an exposure.

In Figs. 1, 2 and 3, I have shown one form of my invention wherein a tray I is positioned beneath anexamination table or the like II in the usual manner. In the central portion of this tray is mounted a cassette or film holder I2 which is heldin position by clamping jaws I3'and I4 slidably mounted in slots I of the tray and held in clamping position by a locking lever I6 in a well-known manner. A frame I'I supported by the table II carries a Bucky grid I8 mounted 4for sliding movement in the direction of the arrow of Fig. l. On the left side of the grid frame as seen in Fig. l are mounted brackets I9 which slidably embrace rods 2i! which in turn are xed in position by brackets 2l secured to frame I'I. The right-hand side of the Bucky grid is provided with ears 22 which slide in a portion of frame Il. In the present form of my invention, means for causing an excursion of the Bucky grid is provided in springs 23 which are connected between frame I'I and a projection I9a on one of the brackets I9. In preparing the grid for an excursion, it is pulled toward the observer, as viewed in Fig. l, so that a projection 24 engages behind latch 25. This latch, as clearly shown in Fig. 3, is pivotally mounted on the frame at 23 and is biased toward latching position by means of a spring 21. An arm 28 of the latch lies opposite a plunger 29 operated by a solenoid 30 in a manner presently to be described.

The movement of the Bucky grid is controlled by means of a dashpot device comprising a cylinder 3| mounted in fixed position on frame I'I and having a reciprocable piston 32 connected by piston rod 33 with a bracket 34 mounted on one of the brackets I9 connected with the Bucky grid. Communication between opposite ends of cylinder 3l is provided by means of housing 35, conduit 3S, Sylphon bellows 31, conduit 38 and housing 39. This dashpot device is filled with liquid in the usual manner and the flow of this liquid is controlled through an opening 40 by means of a needle valve 4I which is controlled by knob 42.

It results from this construction that when the Bucky grid I8 is moved by hand so as to place the projection 24 behind the latch 25, thereafter operation of the solenoid 30 will cause the plunger 2S to strike the arm 28, as shown in Fig. 3, so as to move the nose of latch 25 in counterclockwise direction about the pivot 26 thus releasing the Bucky grid to the control of the springs 23. These springs then cause the grid to make an excursion, the speed oi which is controlled by the dashpot device including the cylinder 3I and the piston 32. l

Mounted on the jaw I3 of the clamp for the cassette I2 is a housing 43 in which is mounted a movable switch member 44. This switch member has an electrically conductive arm 44a on which are mounted two pairs of contacts 45 and 46. A spring l? normally urges the switch member to the dot-dash position indicated in Fig. 2. When a cassette I2 is in proper position in the tray, it moves the plunger 44 to the full line position of Fig. 2. When the switch member 44 is in this full line position the contacts 48 are in engagement with the contacts 45 as shown in Fig. 4. When the switch member 44 is in the dot-dash position of Fig. 2 then the spring 4l fand' line 6o through con e l. 4lmally 'open contacts 62 whichlead through lines urges the contacts 46 into engagement with the contacts 49. t y

Referring now to Figs. 1 and 4, switches A, C and B are shown mounted toward the left-hand side of Fig. 1 and controllable by a projection 50 mounted on the Bucky grid. The contacts "of these switches are all inside the housing 5I mounted on the frame I'I. When the Bucky is in latched position as shown in dot-dashllin'es in Fig. 4, the projection 5Il'has carried switch, C to closed position and has caused the nose V52 of the switch blade to engage switch A so as to open it. At this time switch B, which' is normally closed, is in its closed position as shownin dot-dash lines in Fig. v- 4.

To initiate an which completes a circuit through line 54, contacts 48 and 45, line 55, switch C, line 56, solenoid 30 and line5I. Solenoid 30, when energized,

,cursionof 'thegridto start, controlled vby the dash-pot device previously described. Immediately after the 'grid startsits excursion, the projection 50 causes the nose 52 to release switch @blade A which`is'only slightly open and allows this switclitoiclose' to its full line positionl as shown in Fig.` 4. This completes a circuit from "L1 through line 58, switch A. line 59, switch B which `at`this time is Yin its dot-dash position) This closes nor- 63 and 64 to'an X-ray transformer to 'initiate an X-ray exposure in the usual manner. At

:the fefndof anexposure. the' grid projection 50 engages switch B so'as`to open thesam'e moving it to the full line 'positionv of Fig. 4. This stops the X-ray exposure. Aswitch A :was''peneddring the excursion of the grid,'the switch C wash'pe'ned which deenergized the vs ol'enoid (3U.

Shortly after the This solenoid-energizing circuit stays open until the" grid is again relatched VorV recocked ready forfthe `neXt operation.

"It'must be robvious Vfrom the above descrip- ,t`io n that if there were no cassette or film holder I 2 I properly`pos itio`ned in the vtray I0 then the switch member 44 instead of beingfin the posirtion, shown in Fig.. 4, would be in the dot-'dash position of Fig. 2. 'I his'wouldfopen Ithe lcontactsfi and theX- ray initiating circuit above described 'would be disabled.

Conversely, ifl a cassette were'positionedin the trayready f or the making cfa radiograph,

` unle ss the grid I8 were 'cocked and latcliedlk as vshown in` dotdash lines in Fig. 4, no exposure ,couldbe initiated because the switches 'A,'B and C wouldbe'in' the full line vpositionof Fig, 4

vrt1t1 1.1 s. disabling the X-ray exposure initiating circuits. x.

,It should be notedthat, in the absence of a cassettel properly positioned, the switch member ,44 isin a positionto cause contacts 46and 49- to engage as indicated in Fig. 4.

Thus upon depression of the button 53, the X-ray tube could be energized through line 65. contacts 46 and 49, lines 66 and 60 and coil 6 I.

Another form of my invention is indicated in ,Figs 5Y and 6. It should be understood that all parts previously described form a portion of this -modication except those changes which are here described. Here a switch 61 is so positioned A source of electric current is indicated at L1, Lz. exposure, the operator now closes the button53 a cassette or film holder is placed in the tray III. This closes the switch 6,1 in the same manner `that contacts 48 are closed with 'contacts 45 in the diagram of Fig. 4. In other words, the

switch 61 may be substituted for the coacting r`vcontacts 45 and 48 in the diagram of Fig. 4. Here "again, it i'snecessary when the cassette is properly placed in position for a radiograph to rst cock and' lat'ch 'the Bucky grid before an X-ray exl'easable holding means formaintaining said third named means in preset condition prior to an `excursion of 'saidf grid, release means for lsaid holding means, aswitch closed by'presetting'ofsaid third named'meansandan electrical circuit-includingfin series, said switch andV said v release means and means responsive to a film holder positioned to receive' rays from said'tube. V

2. In combination, means for energizing an X-"ray tube, means for exposing a radiographic lm to thefrays'from said'ntube including'a lm "holder 'and a Bucky gridya spring requiring'cocking forcausingv 'an excursiono'f Vsaid grid, a switch closed'by" cooking of said' spring. a switch closed by aA lm holder inposition'to receive rays from said'tube, and means controllingsaidrst named meansin'cluding both of'said switches in series. 3. In combination, a Bucky grid, arst switch closed` thereby, almholder, two switches `con-- trolled by`said holder'including a second switch closable responsivez to 'said' holder loaded-and a. third switch closable'res'p'onsive to said holder empty, and. alternative means for energizing-an grid, a' latch for holding s'aidfspring means cocked, electrically operated release means for said latch, af switch Abpen'able by cooking movement of said grid and closable by'starting excursion X-ray tube including on the one hand saidrst vand second V switchesfin series and on -the'oth'er hand'saidf'third 'switch only.

4. 1n combination, a cassette, a' grid 'positioned over said cassette for movement relativethereto, spring means forcausingan excursion of' said jope'nable byintermediate excursion movement of Saidgrid, a switch responsive to'po'sitioningof saidfcassette beneath said grid, velectrically operated X-'rayexposure Vini tiating 'means, an electricalcircuit including in series an operatoroperable member and said cassette 'responsive 'switch' and' said switch CV and' said' release means. Yand an electrical circuit' includingin series said switchesA and B vandsaid X-ray exposure initiating'means. ,y Y

' EDWARD B. GRAVES.

, 'fFER'ENdES CLITED, The.A following referencesareof record inthe file of this patent:

'UNITEDl STATES PATENTS Number Name Datev 1,592,279 .'Lechenger July 13, 1926 1,919,457 Drum et al. Nov. 6,1934 2,145,868 v Fischer Feb... 7, 1939 2,241,516 pedin vMay 13, 1941 2,466,355 Baker Apr. 5, 1949 

